Solar + Battery + EV + Heat Pump: How to Build a Future-Ready Melbourne Home

The starting point should not simply be: "How much solar do I need today?" It should be: "What is this home likely to use over the next several years?"

The Australian Government recommends considering both current and future electricity consumption when sizing a solar system. Future EV ownership, increased air-conditioning use and switching from gas to electric appliances can all change household electricity demand.[reference:1]

This is why the individual technologies should not be designed in isolation. A solar system should not be designed without considering the future EV. A battery should not be sized without considering solar generation and evening demand. A heat pump should not be selected without considering hot-water usage and operating conditions. And a new EV charger should not be installed without considering the home's electrical infrastructure.

Solar is usually the foundation of a home electrification strategy because it creates electricity that can be used by several other systems.

A single solar system can potentially supply: household appliances, lighting, air conditioning, heat-pump hot water, EV charging, battery charging and other electric loads.

There is no single solar size that is right for every Melbourne home. A suitable system depends on: electricity consumption, roof size, roof orientation, shading, household occupancy, daytime electricity use, EV charging, hot-water system, air conditioning, battery plans, inverter capacity, network requirements and future electrification.

These should be treated as starting system configurations rather than universal recommendations. The correct answer comes from the property and its energy profile.

Generating more electricity is only part of the equation. You also want to use electricity efficiently.

Solar → Home is generally straightforward. But you can also have: Solar → Heat Pump, Solar → EV, Solar → Battery. This is where electrification becomes interesting.

Instead of having separate systems operating independently, the home becomes an interconnected energy system.

Hot water is a significant household energy use. The Australian Government estimates water heating accounts for around 25% of an average household's energy use. It also identifies heat pumps as a highly efficient electric hot-water technology.

A heat-pump hot-water system can potentially be scheduled to operate when solar electricity is available. Solar Victoria specifically requires eligible heat-pump hot-water systems to have configurable timing or the ability to operate in connection with solar PV generation.[reference:2]

The hot-water tank effectively becomes a form of thermal storage. That makes heat-pump hot water particularly relevant to a smart solar home.

Electrification does not mean buying the biggest appliance available. Solar Victoria's current guidance recommends considering household hot-water consumption, occupancy, future household needs, winter conditions, solar self-consumption, tank size and operating temperature.

Solar Victoria Tank-Sizing Guide

Solar Victoria recommends around 75L of stored hot water per person as a general guide, while recognising that actual consumption varies. Oversizing is not automatically better. Solar Victoria notes that oversized units can cost more, be less efficient and cycle on and off more frequently.[reference:3]

A battery solves a different problem from solar. Solar generates. A battery stores.

The battery is particularly useful when you generate electricity during the day but consume a significant amount after the sun goes down. However, a battery should not automatically be the first addition. If your heat pump and EV can use solar directly during the day, there may be less reason to route that electricity through a battery.

You may see batteries advertised as 5kWh, 10kWh, 13.5kWh or 15kWh. But the biggest battery is not automatically the right battery.

Consider usable capacity, evening electricity use, solar surplus, battery charging power, discharge power, efficiency, warranty, backup requirements, EV charging, electricity tariff and future household demand. A home with modest evening electricity consumption may not fully utilise a very large battery.

An EV is essentially another major electrical load. For a vehicle travelling 40km/day at 18kWh/100km, the calculation is:

That electricity has to come from somewhere. It can potentially come from: Solar → EV, Solar → Battery → EV, Grid → EV, or a combination. The charging strategy matters almost as much as the vehicle's energy consumption.

Suppose your EV is normally at home between 10am and 3pm. You may be able to use solar directly. If the vehicle is away during the day and returns at 6pm, direct solar charging becomes more difficult. The same EV can therefore create very different energy requirements depending on the household's routine.

A smart charger can help coordinate charging around solar generation, household electricity use, battery state of charge, electricity tariffs and vehicle requirements.

Air conditioning is another reason to think about future demand. Melbourne households may have reverse-cycle split systems, ducted air conditioning, multiple split systems, heat-pump heating or electric heating.

A home that uses little electricity during mild weather can have substantially higher demand during a hot or cold period. Solar can help cover daytime cooling demand. A battery can potentially support evening loads. But the system still needs to be sized around realistic consumption. This is another reason why annual electricity consumption alone is not enough.

A future-ready home should not operate as a black box. You want to understand solar generation, household consumption, battery charge and discharge, grid imports and exports, EV charging and major appliance consumption.

Monitoring can help identify patterns that are otherwise invisible on a monthly electricity bill. For example, you might discover: high solar generation, low daytime use, high exports and high evening grid imports. That immediately raises a question: would load shifting or battery storage make sense?

This is one of the most overlooked parts of home electrification. You may want 10kW solar, a battery, an EV charger, a heat pump, air conditioning and an induction cooktop. But the home's electrical infrastructure also needs to support the equipment.

The installer may need to assess switchboard capacity, circuit protection, available space, cabling, phase configuration, main switch, electrical load, EV charger requirements, battery connection and solar inverter requirements. Solar Victoria is actively supporting training around switchboard upgrades for home electrification, reflecting the increasing importance of electrical infrastructure as households add more electric technologies.

Your home's electrical connection can affect the design. A household with several high-power electrical loads may need a more detailed assessment of solar inverter, EV charger, battery, heat pump, air conditioning, switchboard and network connection.

Three-phase does not automatically mean a household needs a particular solar configuration. Likewise, single-phase does not automatically prevent you from installing a larger solar system. The actual design needs to be assessed against the property's electrical connection and local distributor requirements.

One of the biggest mistakes homeowners make is assuming future-ready means buying every technology immediately. It doesn't. A staged approach can often make more sense.

Victoria is introducing significant building electrification changes.

New homes: From 1 January 2027, new residential buildings must be built all-electric. That means new-home planning needs to consider electric hot water, solar, heating and cooling, cooking and EV readiness.[reference:6]

Existing homes: From 1 March 2027, if an existing home's gas hot-water appliance breaks and cannot be repaired, it must be replaced with an electric alternative. There is no equivalent requirement at that date for every existing gas cooktop or gas space-heating appliance to be removed. The Victorian Government does, however, encourage households to consider efficient electric alternatives.[reference:7]

This distinction matters. You don't need to turn every existing Melbourne home into a fully electric property overnight. But if you're already upgrading your energy system, future electrification should be part of the conversation.

A future-ready Melbourne home could look something like this:

The goal is not energy independence at any cost. The goal is to coordinate generation, consumption and storage intelligently.

Consider a hypothetical Melbourne household: 4 occupants, 15kWh/day current electricity use, EV travelling 40km/day, heat-pump hot water, reverse-cycle AC, future battery and good roof space.

Then consider heat pump, AC and future electrification. The final electricity requirement could be significantly higher. Rather than immediately selecting the largest solar system, the installer should model: current consumption, EV demand, heat-pump operation, AC usage, roof generation, battery requirement, daytime self-consumption, evening demand, export limitations and future loads. This is what whole-home energy design means in practice.

Victoria's new Midday Power Saver program adds another variable. Eligible households can access free electricity between 11am and 2pm.[reference:8] The program is designed to encourage households to move flexible electricity consumption into the middle of the day.

Potential flexible loads include EV charging, heat-pump hot water, washing machine, dishwasher, dryer and battery charging. For a solar household, this does not necessarily replace solar. Instead, it adds another way to think about when electricity is consumed. The best strategy will depend on your retailer, tariff, solar generation, battery settings and household routine.

Electrification technologies can have different incentives and eligibility rules.

The important point is simple: check current eligibility and program status before you buy.

There is no universal order, but this framework is useful.

The starting point should be the home rather than a product list.

Without monitoring, you may not know how much solar you're using, how much you're exporting, when your battery charges, when your EV charges, how much electricity your heat pump uses or how much electricity you buy from the grid.

With monitoring, you can make decisions based on your home's actual behaviour. High midday export combined with high evening grid use may suggest that battery storage deserves investigation. But high daytime consumption with low export could indicate that you're already using a large proportion of your solar directly. The data comes first.

"Future-ready" does not mean: Buy everything. It also does not mean: Install the biggest solar system, biggest battery and most powerful EV charger available.

The right design depends on the home. A future-ready system should be appropriately sized, compatible, safe, financially sensible, expandable where practical and suitable for the property's electrical infrastructure.

A future-ready Melbourne home is not about installing every energy product available. It is about making the products you choose work together.

That approach becomes increasingly relevant as Melbourne households add EVs, replace gas appliances and look for ways to control electricity costs. And the best time to think about future electrification is usually before the next major appliance is installed.

• Solar Victoria — Solar Panel (PV) Buyers Guide
• Solar Victoria — Solar Assessment Calculator
• Solar Victoria — Solar Panels and Energy Efficient Hot Water Systems
• Solar Victoria — Hot Water Rebate
• Solar Victoria — Deciding Your Hot Water System Size and Tank
• Clean Energy Regulator — Solar Batteries
• Clean Energy Regulator — Changes to Rebate for Solar Batteries from 1 May
• DCCEEW — Cheaper Home Batteries Program
• Victorian Government — Midday Power Saver(verified alternative)  
• Victorian Energy Compare